DailyDirt: The Little Things In Physics Make Big News

from the urls-we-dig-up dept

Scientific discoveries often build upon past scientific discoveries, and it looks like investments in huge particle colliders are really paying off now. But even without gigantic particle accelerators, physicists have been taking some cool measurements recently. Here are just a few examples of some significant discoveries in physics that are verifying some of our models of how the universe works.

Re: FTL neutrinos

The calculated transit time of the electronic signal over that cable was being subtracted from the measured time of arrival of the neutrinos at Gran Sasso, to compensate for signal delays. Because the cable was loose, the signal was taking longer than calculated to reach its end, by 54 nanoseconds I think it was. Hence the neutrinos were thought to be arriving that much sooner.

54 nanoseconds is the time it takes for light (or the neutrinos) to travel 18 metres. The 700km distance between the LHC and Gran Sasso was known accurately enough to discern a timing discrepancy that small.

High-energy physics is a complicated business these days. It took 3 years of careful checking before the researchers concluded that they couldn’t find any obvious source of the error. And even after the result was released, it took more than another year before the loose cable was discovered.

Re:

Probably. Measuring the existence of a particle isn't the kind of thing that can be easily faked by some delayed messaging. Those are very complicated readings, and the fact that they're showing us exactly what we expected to find would be an incredible coincidence if it turned out to be faulty equipment. The neutrino story, on the other hand, made about as much sense as this. That bumped up the chance of wrongness there.

Some astrophysicists say they've discovered a filament of dark matter between two galaxy clusters about 2.7 billion light years away. This filament of dark matter appears to be around 58 million light years long, and the astronomers were lucky to find two galaxies oriented in a way that allowed them to measure the effects of this dark matter trail.

You know... All these space-based discoveries that scientists make, which are based on them measuring minute bits of light, are kind of like me discovering a swinging door in China by measuring wind patterns in the US.